Here’s a short Christmas story from “The Class of ’65” that shows something we can be thankful for. It happened 50 years ago this month in a time and place that seems familiar yet so far away.

A group of people from Koinonia drove into Americus to hear a visiting minister speak at the largest church in town, First Baptist. Among them were the community’s leader, Clarence Jordan; a couple of newcomers, Millard and Linda Fuller; and a recent high school graduate soon to leave for college, Greg Wittkamper, the main character of my book. One of Greg’s best friends was with them, too: Collins McGee, a civil rights activist who worked at the farm. Collins (as you can see in this photo with Greg) was black.

As the Koinonia party entered the church, an usher became visibly alarmed at the sight of a black hand reaching for a bulletin.

“Who’s he?” he asked.

“Why, that’s Collins McGee,” Greg answered innocently.

The congregation was singing “It Came Upon a Midnight Clear” as the Koinonians took their places in a pew. Just as they came to the line about “peace on Earth, goodwill to men,” the usher hurried over and grabbed Collins by the collar.

“You’ve got to get out of here,” he commanded.

The Koinonians knew First Baptist was segregated, but they had hoped that their interracial group would be allowed to join the worship service in the spirit of the season. Not a chance. They left peacefully. Outside the sanctuary, Clarence looked back at the church and was struck by the way its white columns and floodlit steeple stood out against the vast night sky. He reached for a preacherly metaphor. “I want you to notice,” he told everyone, “how much darkness there is.”

I heard this story from two different participants a quarter of a century apart. Millard Fuller first told it to me in 1987 when I was writing a profile of him and his work as one of the founders (with his wife, Linda) of Habitat for Humanity, the housing ministry that traces its roots to Koinonia. Years later, when I was working on “The Class of ’65,” Greg Wittkamper told me the same anecdote as we were sitting on his deck in the mountains of West Virginia. The experience of being turned away from a Christian church because one of their party was black left a deep impression on them. But they weren’t surprised. Despite the new civil rights laws, that’s the way things were in Americus and many other places in America.

I’ve thought of this story several times this year as I’ve spoken about my book. A good many people have asked whether I think race relations have really improved since the 1960s. It’s a legitimate question. When every month brings news of confrontations with police and hate crimes and more rancor and distrust, you have to wonder.

I’m retelling this Christmas tale now because it shows in its small way what things were like not too many years ago. It also shows how things that once seemed immutable do change. That church eventually dropped its restrictive policies when its membership realized that exclusion was not in keeping with their faith.

Clarence was right: There’s a lot of darkness out there. But there’s also light, and most of us, when we search our souls, are drawn to it. For that, we should be grateful.